This past weekend, I was running my engine for about 30 minutes when I noticed a "hot" odor in the cabin. A quick check of the temperature gage showed a normal temperature of 160. Water was pumping out with the exhaust and it looked norma. I pulled the engine cover, and the engine smelled hot, seemed to be some smoke/steam coming from the bottom of the engine. We shut it down, let it cool and checked all engine fluids which were at normal levels. I ran the engine for about 20 minutes coming back into my slip without further incident. I should add that I haven't done any engine work recently, and the last time we used the boat, we ran the engine for extended periods of time without any problems. This coming weekend, I'm planning to take the boat south for a race. I'm a little concerned, and wonder if anyone has experienced this, and/or have any suggestions on what might be wrong.
Dave Motter
Sweet Sue II
Hull #177
Everett, WA.
A true hot engine with somewhat normal temperature can sometimes be an airlock in the cooling system and usually happens after the cooling system has been serviced. Have you burped your engine lately? Did you clean your engine lately? If this is not the case and the hot engine smell is sweet like coolant, I'd check to make sure the coolant system is tight, especially the hoses going to the heat exchanger. I'd also check to make sure the raw water system is tight, especially the hoses going to the heat exchanger. Check the weep hole in the raw water pump too.
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Agree about the burping, but it also could be a blockage. I had this happen last time I changed the antifreeze. I removed the thermostat and I still had the problem.
To narrow the issue: When the coolant is cool, remove the thermostat and replace the short black hose between the thermostat and the coolant pump with a clear vinyl hose. Run the engine and see if coolant is flowing through the clear hose. I wouldn't let it run too long. It might melt the vinyl hose. If you don't see coolant flowing, you probably have a coolant blockage somewhere.
Ben Ethridge
Miami, FL
1984 MK1 Hull# 263
Thanks for the suggestions......found the source of the problem. The alternator belt was loose, and slipping causing the friction and the "hot" smell. I've replaced it and tightened it up. Ready to go again.
Dave Motter
Sweet Sue II
Hull #177
Everett, WA.
I usually run my engine at 2200 RPMs. I became aware of the "hot smell" when I was below in the cabin while my cabin boy was at the helm. His boat he ran at higher RPMs with a Westerbeke, so he thought he would give it a little boost to go through an area of current at the East end of Long Inland NY. Putting it up at 2800 RPMs, without permission clearly resulted in "the smell". Now I keep a better eye on those who know about their boats.
Gary Matthesen
"Holiday"
1987 #50646
Oyster Bay Long Island NY